There's water, water everywhere in National Geographic News's most popular space coverage of 2009: A probe proved there's water on the moon, a Mars lander's leg got all wet, fishlike life may swim a Jupiter moon's seas, and more.
| 10. Star Crust Is Ten Billion Times Stronger Than Steel|
Move over, Superman. The Man of Steel has nothing on the collapsed cores of massive snuffed-out stars, which constitute the strongest known material in the universe, a May study said.
| 9. Could Jupiter Moon Harbor Fish-Size Life?|
"I'd be shocked if no life existed on Europa," one scientist said—and provocative research described in November suggested the moon's seas have enough oxygen for fishlike animals.
| 8. 32 New Planets Found Outside Our Solar System|
The massive haul of new worlds brings the number of known extrasolar planets to more than 400, astronomers announced in October.
| 7. Liquid Water Recently Seen on Mars?|
Mars pictures taken in Summer 2008 showed strange globs on the leg of the Phoenix Mars lander that seemed to behave like liquid water, a February paper reported.
| 6. Most Earthlike Planet Yet Found May Have Liquid Oceans|
Measurements announced in April suggested that the planet known as Gliese 581d has a lot more in common with Earth than first thought—and it has a previously unknown sister planet that is the lightest yet found.
| 5. Particles Larger Than Galaxies Fill the Universe?|
The oldest of the subatomic particles called neutrinos might each encompass a space larger than thousands of galaxies, according to new simulations described in June.
| 4. First Proof of Ancient Mars Lakeshores Found|
High-resolution pictures of a Martian valley revealed three-billion-year-old shorelines along what was once a body of water about the size of Lake Champlain, researchers said in June.
| 3. Water on the Moon Confirmed by NASA Crashes|
It's official: There's water on the moon—and a "significant amount" of it too, members of NASA's moon-crash mission, LCROSS, announced in November.
| 2. Green "Two-Tailed" Comet Buzzed Earth on One-Time Visit|
When it swung through our solar system in late February, the recently discovered comet Lulin seemed to have a second tail and a green glow—and the sight will probably never again grace our nighttime skies.
| 1. Sun Oddly Quiet—Hints at Next "Little Ice Age"?|
In May the sun was still the most sluggish it had been in decades, prompting concerns about a cooling effect on climate—but the dip in solar activity wouldn't be likely to fight global warming, researchers cautioned.
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